269 



Gyro. 



of surface showing revolving and cross lines. — In the Niagara 

 limestone^ Hartville, Ind. — Vh. 



Gyroceras undulatum. See Cyrtoceras undulatum. VII. 



Halonia flexuosa. ( UlodenrJron Uexnomim^ Goldfuss, 



Flor. Sarr. 

 X/// .^tim. .>-^?&jk^^f • ^' Vol. 2, plate 



2, fig. 10.— 

 Lesq. Coal 

 Flora, page 

 416,plate6]' 

 fig. 3, from 

 Lacoe's col- 

 . - 1 ec tion at 

 JnclJn5. -^^F ^/./^.Pittston, 



Fa.) Collett's Indiana Rt. 1883, plate 18, fig. 1,—XIII? 

 Halonia regularis. See H. tuberculata. XIII. 

 Halonia tortuosa is not H. tuberculata. XIII. 

 Halonia tuberculata. (Brongniart, Histoire des vegetales 

 1 X ///, tiid,jjS;3 ^^^^^y^r^'^ V fossiles, 1828)Collett's In- 



¥^\^A^#^ diana Rt. of 1883, page 

 WW^Ml 87. relate 18. fi^. 4-. fftee 



e- 



M# f ' Pl-te 18 fig. 4. [S. 

 ? AY\WyI*'W Lesquereux's nne repr 



sentation on plate 74, fig. 

 9, in his Coal Flora of 

 Penn. and U. S. (bound in 

 Vol. 1, between pages 

 560 and 561,) description 

 on pp. 411, 412. This 

 beautiful specimen in the 

 Cabinet of the Geol. Sur- 

 vey of Pa. obtained in 

 1879, by Dr. Chance in 

 Venango Co., Pa., 3 miles 

 south of Oil City, from the base of the Conglomerate {XII), is 

 an impression on very soft, fine grained sandstone, of the bark 

 with perfectly preserved leaf scars. Halonia tortuosa of the 

 English is not identical with H. tuberculata of Brongniart, which 

 last, like the American specimens in Illinois Rt. Vol. 4, plate 

 29, fig. 1, represents Cyclocladia ornata^ Goldfuss, with its bark 

 removed. H. regularis may be a different species. Lesq. — XII 



